The IOS feature set for routing and switching is unmatched in the industry, delivering functionality required for business critical applications. Preserving these advantages of IOS to our customers is critical for Cisco. IOS XE retains the exact same look and feel of IOS, while providing enhanced future-proofing and improved functionality. In IOS XE, IOS 15.0 runs as a single daemon within a modern Linux operating system. Additional system functions now run as additional, separate processes in the host OS environment. The operation, support and management of IOS XE does not require re-training from classic IOS.

Question No: 75

On Cisco IOS-XR, which command is used to review previous configuration events committed on the router?

show configuration history

show configuration commit changes

show configuration commit list

show configuration commit failed

Answer: C

Question No: 76

What is the advantage of running IOS-XE individual consolidated packages versus subpackages?

decreases storage requirements

optimizes router memory usage

simplified installation

lowers CPU utilization

Answer: B

Question No: 77

Which three statements about VLAN implementation in a Layer 2 switch environment are true? (Choose three.)

The Cisco IOS switchport access vlan interface configuration command is used to configure the native VLAN on the switch port.

802.1AD supports VLAN overlap.

VLANs can span across multiple switches.

802.1Q encapsulation is used to identify different VLANs on a trunk port.

Inter-VLAN routing is performed between VLAN tunnel ports.

Answer: B,C,D

Explanation: Explanation/Reference:

IEEE 802.1ad[note 1] is an Ethernet networking standard informally known as IEEE 802.1QinQ and is an amendment to IEEE standard IEEE 802.1Q-1998. The technique is also known as provider bridging, Stacked VLANs or simply QinQ or Q-in-Q.

The original 802.1Q specification allows a single VLAN header to be inserted into an Ethernet frame. QinQ allows multiple VLAN headers to be inserted into a single frame, an

essential capability for implementing Metro Ethernet network topologies. Just as QinQ extends 802.1Q, QinQ itself is extended by other Metro Ethernet protocols.[specify] In a multiple VLAN header context, out of convenience the term quot;VLAN tagquot; or just quot;tagquot; for short is often used in place of quot;802.1Q VLAN headerquot;. QinQ allows multiple VLAN tags in an Ethernet frame; together these tags constitute a tag stack. When used in the context of an Ethernet frame, a QinQ frame is a frame that has 2 VLAN 802.1Q headers (double- tagged).

There is a mild confusion regarding the naming because the 802.1ad standard was grown out of the 802.1QinQ protocol (which was developed based the trademarked method 802.1Q, with capital quot;Qquot; as a distinction instead of the 802.1q as the standardised protocol) which originally used 0x9100 as ethernet type instead of 0x88a8. While the network industry usually mix the naming the proper, standardised name is 802.1ad which sometimes gets appended by the other alternative names mentioned above; the plain quot;802.1QinQquot; name usually refers to the old standard which is now considered obsolete

Resilient Ethernet Protocol (REP) on the Cisco ME 3400E Ethernet Access switch. REP is a Cisco proprietary protocol that provides an alternative to Spanning Tree Protocol (STP) to control network loops, handle link failures, and improve convergence time. REP controls a group of ports connected in a segment, ensures that the segment does not create any bridging loops, and responds to link failures within the segment. REP provides a basis for

constructing more complex networks and supports VLAN load balancing.

Question No: 79

After configuring Q-in-Q on a new interface, the customer has requested that the IOS version and remote model also be viewable via the trunk. What additional command would need to be applied to both sides of the Q-in-Q trunk?

l2protocol-tunnel cdp

l2protocol-tunnel stp

l2protocol-tunnel vtp

l2protocol-tunnel lldp

l2protocol-tunnel odr

Answer: A

Question No: 80

What is a requirement for performing Cisco IOS ISSU on the Cisco IOS XE-based ASR 1006 and ASR 1013 routers?